Wilson wins grant to explore rare earth element opportunities
The 17 metallic rare earth elements – 57 to 71 in the periodic table plus scandium and yttrium – are essential resources used in a wide range of technological applications. They are found in wind turbines, liquid crystal displays, batteries and portable electronic devices.
Since the purified form of these elements is mainly sourced from foreign countries, the US supply chain for rare earth elements presents a problem.
Justin wilson, associate professor of chemistry and chemical biology at the College of Arts and Sciences, received a grant from the US Department of Energy Basic Energy Sciences Program develop more efficient methods of separating rare earth elements that will make their domestic availability economically viable.
Although natural mineral deposits of rare earth elements are present in the United States, environmental and cost concerns make them economically inaccessible, Wilson said. Thus, the majority of rare earth elements currently come from foreign countries, such as China, where environmental regulations are less stringent. In nature, these elements are always found mixed within the same mineral deposits. As such, the main economic and environmental factor in obtaining rare earth elements in their pure forms is their separation.
Because these elements have similar chemical properties, their separation is not trivial, Wilson said. Current methods require several steps in a process known as liquid-liquid extraction which is energy intensive and produces a significant amount of hazardous waste.
“The more efficient and environmentally friendly separation of rare earth elements is a chemical problem at its heart,” Wilson said. “We are delighted to apply our expertise in this area to address this important issue. Given the widespread use and growing demand for new technologies and devices using rare earth elements, we hope that our separation strategies can make these critical resources more widely available in the United States.
Wilson’s project addresses these challenges by exploring new strategies for separating rare earth elements. The project is studying chemical receptors, or ligands, which can bind, or chelate, different rare earth elements with different degrees of efficiency or affinities. By adjusting the relative affinities of these ligands, Wilson aims to use this approach to design separation strategies to differentially extract chemically similar rare earth elements. This research will strengthen the basis for more efficient domestic separation of rare earth elements.
The first objective of this project is to design and synthesize new ligands to modify their rare earth selectivity profiles. Further modifications of the ligand to modify the so called “secondary coordination sphere” of rare earth elements are targeted in the second objective. In the end goal, these ligands are applied to demonstrate the separation of individual rare earth elements using solvent extraction techniques.
With this project, Wilson hopes to find more energy-efficient and environmentally friendly ways to separate rare earth elements, making purified critical resource supply chains accessible in the United States.